The invention relates to homogeneous catalysts for the metathesis of acetylenes (alkynes), a process which is defined as the redistribution of alkylidyne moieties in a mixture of alkynes.
For example, EQU 2XR'C.tbd.CR.sup.2 .revreaction.R'C.tbd.CR'+R.sup.2 C.tbd.CR.sup.2.
Prior to the present invention, there has been no report of a homogeneous tungsten catalyst for the metathesis of alkynes. Two types of alkyne metathesis catalysts are known, heterogeneous catalysts containing tungsten which operate inefficiently at 300.degree.-400.degree. C. (F. Pannella, R. L. Banks and G. C. Bailey, J. Chem. Soc. Chem. Comm., 1548 (1968)), and a homogeneous catalyst system made from Mo(CO).sub.6 and phenol in toluene (A. Mortreux, J. C. Delgrange, M. Blanchard and B. Lubonchinsky, J. Molec. Catal. 2, 73 (1977); S. Devarajan, O. R. M. Walton and G. J. Leigh, J. Organometal. Chem., 181, 99 (1979)). None of the prior art has identified the catalytically active species or site.
It would be desirable to provide a homogeneous catalyst for the metathesis of acetylenes because it, like olefin metathesis, allows manipulation of hydrocarbon feedstocks in the chemical industry.